Kuunteluarvio:Dunlavy SC-IV/A

High-end Monitoring with the Dunlavy
SC-IV/A

Tom Jung

John Dunlavy is one of the most respected names in the world
of high-end audio, designing and building speakers for more than 25 years. Dunlavy Audio
Labs manufactures loudspeakers that range from small, twoway speakers up to four-way
systems with monitors that weigh up to 550 lb. each.

The SC-IV/A is a three-way, five-drive tower that is 6' tall
and weighs 190 lbs. Two 10" woofers are located on the top and bottom of the 12"
wide cabinet. In the middle of the two woofers are two 5" midrange drivers and
between them sits a I" fabric dome tweeter. These five symmetrically placed drivers
are housed in a sealed enclosure.

A first order crossover network (6 dB/octave) is employed for
minimum phase distortion. The woofers are closest to the listener while the midrange
drivers are farther back and tweeter back still farther. This is done to insure accurate
time alignment.

Dunlavy speakers are famous for their accurate frequency
response. The SC-IV/A is rated within plus or minus I dB from 25 Hz to 20 kHz - now that's
flat. Diffraction is almost eliminated with a Dunlavy-patented process that uses heavy
felt surrounding the midrange and tweeter drivers.

Accuracycounts

The SC-IV/A is one of the most accurate speakers I know of,
with extended frequency response usable down to 20 Hz. Impedance is 5 ohms nominal, with a
minimum of 3 ohms and a maximum of 7.5 ohms. This, when combined with a sensitivity of 91
dB at 1 W/1 meter, makes the Dunlavys relatively easy to drive. Each pair of Dunlavys is
matched within plus or minus 1/4 dB!

Dunlavy Audio's Colorado Springs facilities house two
anechoic chambers. John Dunlavy is a fanatic on measurements; drivers are individually
measured and matched within a system. In fact if you blow a driver, one matched to the
surviving mate can be purchased from Dunlavy; the company keeps records of individual
driver measurements on file for each speaker system. Impulse response, step response as
well as spectral time delay response are measurements proudly displayed with each model on
the Dunlavy Web site, www.dunlavyaudio.com.

Using high-end consumer speakers for professional monitoring
is a potentially risky matter. High-end speakers may not be typical of what the general
public listens to music on, and -possibly not valid reference. High-end speakers may also
be too flattering, making something sound better than it really is.

I've found in general, the studio is where more professional
monitors are appropriate, whereas in the mastering stages a high-end monitor system seems
to work better. Sometimes a lesser-quality professional speaker can make you work harder
to get things sounding right at the original session, but it is also valid to really hear
all the detail with true accuracy. Switching between these two types of speakers is ideal.

I set the SC-IV/As up in the main control room at Ambient
Recording in Stamford, Conn., and soon realized distance was key. The five drivers need
about 10' between the speaker and the listener to focus properly. Traditionally, these
kinds of speakers are placed out from the forward wall by at least three or four feet,
putting the listener at the back of this average-sized control room. Not good.

Ambient recently sold its rock'n'roll soffit-mounted
monitors, leaving large openings in the walls on either side of the control room glass. I
set the Dunlavys inside the openings and tightly filled the void on either side with
insulation and covered what was left of the opening with several layers of wood, lead and
sheetrock. Now I could sit in the forward part of the room and hear the SC-IV/As focus
beautifully with a slam to the bass that is unique to soffit monitors, but with real
imaging and detail.

Listening tests

I listened to many styles of music with two different
amplifiers over several days. The source was mostly SACD from a Sony SCD- I player. Much
to my surprise I found the amplifiers to have a much different presentation due to the
extreme sense of inner detail and the revealing characteristics of the SC-IV/As. I started
listening with a pair of Monobloc Legacy bipolar amplifiers, which made the Dunlavys sound
extended both top and bottom, very natural and smooth. The low end was very tight and well
controlled even with the fattest acoustic bass.

This is one of the great attributes of a sealed enclosure.
The midrange and top end were detailed but not harsh or hard sounding. You might think
800W a bit much for a 91 dB sensitivity speaker, but think of all that headroom.

Next I tried an interesting amplifier from Denmark called the
GamuT. This amp is a MOSFET design and sounds remarkably like vacuum tubes. The Dunlavys
sounded a bit softer on the bottom but with a midrange and top-end liquidity that sounded
like tubes without the distortion. Even though the SCIV/As are easy to drive, you need a
highquality amp because these speakers are so revealing.

One can listen to the Dunlavy SC-IV/As for hours without
fatigue and hear things you never heard before due to the great inner detail. It is
actually fun to listen to a DSD source through these speakers.

Summary

I plan to review the Legacy and GamuT amplifiers using the
Dunlavy speakers, which become high-resolution tools to hear what's really going on in the
electronics.

I still stand by my guns in that loudspeakers are the weak
link in the reproduction chain, but the Dunlavy SC-IV/As are possibly the most accurate
loudspeakers out there. If you want full-range accuracy and can handle the $8,000 sticker
(which is a mediumpriced high-end speaker), the Dunlavy SCIV/As are well-worth looking
into.